The following relates generally to wireless communications, and more specifically to on-demand retransmission in broadcast communications.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless network, for example a wireless local area network (WLAN), such as a Wi-Fi (i.e., Institute of Electrical and Electronics Engineers (IEEE) 802.11) network may include an access point (AP) that may communicate with one or more wireless or mobile devices. The AP may be coupled to a network, such as the Internet, and may enable a mobile device to communicate via the network (or communicate with other devices coupled to the access point). A wireless device may communicate with a network device bi-directionally. For example, in a WLAN, a device may communicate with an associated AP via downlink (e.g., the communication link from the AP to the device) and uplink (e.g., the communication link from the device to the AP). A wireless personal area network (PAN), which may include a Bluetooth connection, may provide for short range wireless connections between two or more paired wireless devices. For example, wireless devices such as cellular phones may utilize wireless PAN communications to exchange information such as audio signals with wireless headsets.
In some cases, Bluetooth communications may require enhanced quality of service. For example, successful bidirectional transmission of audio information for voice may have a relatively low tolerance for packet loss or timing issues. The link quality between two devices may affect the data rate used for communications (e.g., as poor link quality may be associated with reduced bitrates for more robust communications).
For devices performing Bluetooth wireless communications (e.g., sending and receiving Bluetooth packets (e.g., DH5, 2-DH5, 3-DH5, etc.), a typical packet error rate may be, for example, 5%. In such examples, a receiver may receive a first transmission of one or more data packets correctly the first time 95% of the time. However, to address the packet error that may occur for only 5% of all traffic, all traffic may be retransmitted multiple times. For instance, if a single packet in a string of packets is unsuccessfully received, the entire string of packets may be retransmitted. These multiple retransmissions may cost a significant amount of bandwidth and may result in unnecessarily high throughput. For example, if the number of retransmissions is two, then an overall bandwidth requirement may be three times the audio rate. Additionally, in cases where the transmissions and retransmissions are performed over periodic intervals, system latency may increase. In cases where transmissions are repeated using, for instance, erasure encoding, latency may be increased even more.